Foodie mogul Barbara “B.” Smith and husband Dan Gasby have sold off their multimillion-dollar Central Park South apartment after shuttering their popular B. Smith restaurants in Sag Harbor and Washington, DC.

The pair listed their 35th-floor pad in 2010 for $5.95 million, but closed a deal only recently as they step back from day-to-day operations of their eatery empire. Restaurateur Richie Notar will expand his Midtown hot spot Harlow into the prime B. Smith waterfront Sag Harbor spot.

Sources said Smith has been battling some health issues. But Gasby explained that they’re eyeing a move to a warmer climate while looking to expand their B. Smith licensing brand.

“There is nothing noble about being old in the cold,” Gasby told Page Six. “I’m 60. My wife will be 65. We had a great run for 17 years in Sag Harbor. There’s a difference between quitting and knowing when to quit.”

Gasby further quipped: “I lived on the beach for 16 years in the summers. Never had a boat. Every time you wake up, you have something to worry about at the restaurant. Now I can walk into any other place in the Hamptons without someone telling me, ‘You don’t have enough lobster!’ I don’t want to be ‘13 Years a Slave.’ You realize it’s very important that you enjoy life to the fullest.”

He added of the Sag space: “We were the only black-owned business of any consequence for 55 miles. There might have been more black-owned businesses in Des Moines.”

Smith’s DC restaurant closed in September after 20 years. Her West 46th Street flagship is still open. Of its original nearby Hell’s Kitchen spot, Gasby reminisced, “In 1986, Eighth Avenue was the Avenue of Lost Souls . . . the most dangerous corner in America. It looked like the front line of the Giants coming down the street in drag and guys in shiny suits slapping women.”

He said after selling their co-op, they are considering “going south” to Florida or Costa Rica or Panama, adding he wants to start “a new, fresh approach” to their homeware brand, which already has deals with Walmart and Bed, Bath & Beyond.